Manganese ethylenebisdithiocarbamate stabilized by desiccant; method and package



United States Patent 2,848,297 MANGANESE E'IHYLENEBISDITHIOCARBAMATE STABHJIZED BY DESICCANT; METHOD AND PACKAGE Sanford J. Hill, Wilmington, DeL, assignor to E. I. du,

This invention relates to fungicidal compositions comprising a metal salt of ethylenebisdithiocarbamic acid. More particularly, it relates to methods for protecting such compositions from oxidation in closed containers and to the resulting packaged compositions so protected.

Metal ethylenebisdithiocarbamates have in general fungicidal properties. Two members of the class, namely manganous ethylenebisdithiocarbamateand zinc ethylenebisdithiocarbamate, are currently marketed commercially and used effectively for the control of a wide variety of plant attacking fungi. Manganous ethylenebisdithiocarbamate and fungicidal compositions containing it are described and claimed in U. S. Patent 2,504,404.

Unfortunately, metal ethylenebisdithiocarbamates are relatively unstable on storage. Thus a serious problem has existed heretofore in marketing manganous ethylenebisdithiocarbamate fungicidal compositions, and to a significant though lesser extent in marketing zinc ethylenebisdithiocarbamate fungicidal compositions, because these compounds tend to decompose relatively rapidly on storage in conventional shipping containers such as multi-wall bags, fiber drums, glass bottles, and the like.

It has been found, for example, that commercial formulations containing initially about 70% by weight of manganous ethylenebisdithiocarbamate packaged and closed for shipment in containers such as mentioned above lose from to 50% by weight of the manganous ethylenebisdithiocarbamate content over a six-month period (February-July) under normal storage conditions, with losses in the higher part of the range occurring in relatively Warm areas such as the Gulf Coast of the United States, and lesser losses for example in the New York City area.

It has now been found according to this invention that metal ethylenebisdithiocarbamate fungicidal compositions can be protected against decomposition in closed containers by including within the container a minor amount of a desiccant. The mechanism of the protective action provided by the desiccant is not understood. The result is unexpected since available evidence shows that the decomposition in packaged material not containing a desiccant is relatively independent of the breathing properties of the package and thus the humidity in the air surrounding the package, and since it has also been found that there is relatively little change in the free-moisture content of stored packaged material whether or not it is protected by a desiccant according to this invention.

The term desiccant as used herein with reference to the protective agent is employed in the conventional sense to describe a material that will pick up water if exposed to humid conditions. Such materials are also sometimes called hygroscopic materials or agents. Illustrative of such materials are calcium bromide, zinc bromide, calcium chloride, anhydrous copper sulfate, anhydrous sodium sulfate, low temperature fired alumina, and silica gel. These and other desiccants which will be apparent to those skilled in the art can be used in preparing the packaged compositions of the invention.

The metalethylenebisdithiocarbamate-containing fun-- gicidal composition employed in practicing the methods of the inventioncanbe unformulated metal ethylenebisdithiocarbamate or formulated material. For example, manganousethylenebisdithiocarbamate or other metal ethylenebisdithiocarbamate can be admixed with adjuvants, carriers or other biologically active materials as desired as is disclosed in S. Patent 2,504,404.

In practicing the processes of' the invention, the desiccant is included within the container for the metal ethylenebisdithiocarbama-te fungicidal composition in any convenient manner; placing one or more small porous paper or fabric bags containing the desiccant within the container for the fungicidal composition. Instead of-plaeihg the desiccant in a small bag, it can be placed in any other convenient receptacle adapted for avoiding direct contact of the metal ethylenebisdithiocarbamate composition without preventing vapor passage; if multi-wall bags are used forpackaging the fungicidal composition, the desiccant can, for example, be placed between the walls of the multi-wall bag.

Alternatively if care is taken to avoid the use of a desiccant which is reactive with the metal ethylenebisdithiocarbamate or other components of the fungicidal composition, the desiccant can be directly admixed with the fungicidal composition prior to packaging or it can be introduced loosely in the packaging container before, during, or after introduction of the fungicidal composition.

The amount of desiccant employed in the methods and packaged materials of the invention can be varied rather widely depending upon the relative action of the desiccant used and the period and temperature of storage for which protection is to be required. In general, the desiccant will amount to from about 2 to 15% by weight based on the weight of the composition which is packaged.

In order that the invention may be better understood, the following examples are given in addition to the examples already given above.

Commercial manganous ethylenebisdithiocarbamic fungicidal compositions were placed in various kinds of contained as shown in the tabulation below and stored in a warehouse for six months. Finely divided anhydrous cupric sulfate was included as the desiccant in each container in which compositions were packaged according to this invention. The cupric sulfate was contained within a cloth pack which was enclosed in the container, the amount of cupric sulfate used being shown in the table as percent desiccant and said percentage being based on the amount of packaged manganous ethylenebisdithiocarbamate fungicidal composition in the container. In each case there was a control, that is,

a like packaged composition in which the cupric sulfate was omitted.

Percent Manganous Ethylenebisdithio- Percent earbamate Example Container Desiccant As After Packed Six Months 50 1b., 5 ply multiwall paper 5.5 74.7 68.7 bag with asphalt vapor bar- None 74. 7 58.2 rier. 251b. fibre drum with asphalt 2.1 75.1 68. 7 vapor barrier. None 74. 7 60. 2 3 1b., 2 ply paper bag with 13.2 74.7 68.2 vapor barrier. None 74.7 56. 5 3 1b., 2 ply paper bag with 5 13.2 74.7 68.7 mil. polyethylene liner. None 74. 7 60.6

One relatively simplemanner involves It will be seen from the above examples that the decomposition rate in packages not containing the desiccant was from two to three times as great as the decomposition rate in compositions packaged according to this invention. The analyses for manganous ethylenebisdithiocarbamate given in the above table were determined according to the carbon disulfide evolution method as described by W. K. Lowen, Journal of the Association of Ofiicial Agricultural Chemists, May 1953, page 484 et seq.

The invention has been illustrated in the detailed examples with specific reference to manganous ethylenebisdithiocarbamate because the decomposition problem is acute with that material, and with reference to cupric sulfate as the desiccant in all such examples so that the results would be on a comparable basis. It will be understood, however, that other metal ethylenebisdithiocarbamates and desiccants can be used in place of those shown in the examples. Thus any departure from the foregoing detailed description which conforms to the principle of the invention, namely, to the utilization of a desiccant to prevent decomposition of metal ethylenebisdithiocarbamates on storage in closed containers, is intended to be included within the scope of the claims below.

I claim:

1. A method for protecting manganese ethylenebisdithiocarbamate from decomposition on storage in a closed container which comprises including Within the container a minor amount of a desiccant, suflicient to stabilize the dithiocarbamate.

2. A package comprising a closed container, manganese ethylenebisdithiocarbamate disposed within said container and a minor amount of a desiccant, sutficient to stabilize the dithiocarbamate.

3. A package comprising a closed container, manganese ethylenebisdithiocarbamate disposed within said container and from 2 to 15% by weight base on the manganese ethylenebisdithiocarbamate of anhydrous cupric sulphate.

References Cited in the file of this patent UNITED STATES PATENTS 789,176 Smith May 9, 1905 1,631,903 Van Der Lande June 7, 1927 2,283,867 Flosdorf May 19, 1942 2,428,861 Waring et al. Oct. 14, 1947 2,531,114 Deitz Nov. 21, 1950 2,665,285 Johnson Jan. 5, 1954 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2, 848,297 August 19, 1958 Sanford J. Hill It is hereby certified that error appears in the printed specification of the above numb ered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 28, for "in" read as into hine 44, for "contained" read container column 4, line 13,. for "base-""read based Signed and sealed this 28th day of October 1958.

(SEAL) Attest:

KARL Ho AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Patents 

1. A METHOD FOR PROTECTING MANGANESE ETHYLENEBISDITHIOCARBAMATE FROM DECOMPOSITION ON STORAGE IN A CLOSED CONTAINER WHICH COMPRISES INCLUDING WITHIN THE CONTAINER A MINOR AMOUNT OF A DESICCANT, SUFFICIENT TO STABILIZE THE DITHIOCARBAMATE. 